code: def save_pickle(bst, path):
      with open(path, "wb") as fd:
          pickle.dump(bst, fd)
  
file_path: xgboost/tests/python-gpu/test_gpu_pickling.py
imports: import os
  import pickle
  import subprocess
  import numpy
  import pytest
  import xgboost
  from xgboost import XGBClassifier
  from xgboost import testing
label_desc: Use image node_id 2 for calling a global function with example usage: save_pickle(bst, path) without return types